Tankless Water Heater Leak Repair, Wheaton, IL

How a tankless leak differs

A tankless water heater heats water on demand as it passes through a heat exchanger, instead of storing it in a large tank. That removes the classic failure of a corroded tank, but it adds other places where water can escape. If you have a wall-mounted unit that is leaking, the repair is rarely the same as the repair for a tank heater, and a provider who knows tankless units is worth asking for. This page explains the usual leak points and how water heater leak repair in Wheaton applies to tankless systems.

The guidance is general. Models differ, and a provider needs to see your unit.

Common leak points on a tankless heater

Water connections. The cold inlet and hot outlet fittings at the bottom of the unit can loosen or corrode. Many installations use isolation valves, which have their own seals.

Isolation and service valves. Many tankless units have valves that let a provider flush the heat exchanger. The seals and caps on these can wear and drip.

The heat exchanger. This is the part that heats the water. Scale or corrosion can cause small leaks inside the unit, which may show up as water at the bottom of the case.

The condensate drain. Condensing gas models produce acidic condensate, which drains through a small line. A blocked, cracked or disconnected line can leak or back up.

The pressure relief valve. Some units have one, and it can drip for the same reasons it does on a tank heater.

Internal parts. Sensors, pumps and fittings inside the unit can leak, and many are not user-serviceable.

Scale and why it matters

Minerals in the water can settle inside the heat exchanger as scale. A layer of scale makes the unit work harder, can cause overheating and noise and can lead to leaks over time. Many manufacturers recommend periodic descaling, which a provider does by circulating a mild acid through the unit with the isolation valves.

If your unit has not been descaled in a long time, ask the provider about it during any leak visit. It is not always the cause of a leak, but it often affects how long the unit lasts.

Condensate: a leak that is not water supply

A condensing tankless heater extracts extra heat from the exhaust, and that produces condensate. It is mildly acidic, and it drains through a small plastic line to a floor drain or a neutralizer. If the line is clogged, kinked or loose, water can drip from the unit or the line.

Condensate is not hot supply water, so the leak does not stop when you turn off the cold supply. A provider will check the line, the neutralizer and the connection to the drain. A wet floor under a condensing unit is not always a heat exchanger failure, and it is worth ruling out the drain first.

What to do when the unit is leaking

Turn off the power. Most units plug into an outlet or have a dedicated switch or breaker.
Turn off the gas at the unit's shutoff valve if it is a gas model. Never use a unit you smell gas from.
Close the cold water supply to the unit.
Dry the area and identify where the water is coming from. Look at the bottom of the case, the valves and the condensate line.
Take photos and note the model and serial number from the label.
Call and describe what you see.

If you smell gas, leave the house and call your gas utility from outside.

What a provider will check

A provider usually starts with the visible connections and valves, then the condensate line, then the case and the heat exchanger. If the leak is at an isolation valve or a fitting, the fix can be as simple as replacing a seal or a valve. If water is leaking from inside the unit, the provider can tell you whether a part can be replaced or whether the unit needs to be replaced.

Tankless heaters are more complex than tanks, and parts can be harder to get. Ask whether the unit is under warranty, whether the provider works with that brand and what the parts timeline is.

Venting, gas lines and permits

A tankless heater typically needs specific venting, a gas line sized for its load and sometimes a larger electrical connection. If a replacement is needed, those details affect the price and the permit. In Illinois, plumbing and gas work is regulated and generally requires a licensed professional. Ask for the provider's license number and confirm it with the state.

If your unit was installed a long time ago, ask whether the venting and gas line meet current rules. A leak visit can be a good time to ask.

Keeping a tankless heater healthy

A few routines extend the life of a tankless heater.

Descale the unit as the manufacturer advises, especially if you have hard water.
Clean the inlet water filter screen if the unit has one.
Check the condensate line and neutralizer on condensing models.
Look at the unit and its connections a few times a year.
Keep the area around the unit clear and the vent unblocked.

Related pages: if you also have a tank heater, see Water Heater Leaking From the Bottom, and if water is flowing right now, read Emergency Water Heater Leak Repair.

Questions worth asking on the call

Ask whether the provider works on tankless units, and on your brand. Ask what the visit covers, whether parts are included and what the next step would be if the heat exchanger is the source. Ask whether the unit is under warranty and how to check. Providers set their own prices and this website does not publish them.

If you rent, tell your landlord first. Many leases require approval for repairs.

Repair or replace a tankless unit

Tankless heaters often come with a longer warranty on the heat exchanger than tank heaters do, and many are designed to be serviced rather than thrown away. That makes repair more common than with a failed tank. A leak at a valve, a seal or the condensate line is usually a repair. A heat exchanger that has cracked or corroded through may be covered by a warranty, depending on the model and the age.

If the unit is old, the parts are hard to find or the repair cost is high compared with a new unit, replacement may make more sense. A provider can explain both sides. The decision is yours, and it is fine to take time to compare options if the unit is still delivering hot water safely while you wait with the leak contained.

Tankless units in Wheaton homes

Tankless units are used in newer and renovated homes. Scale from hard water can clog the heat exchanger and lead to leaks or error codes. Note the model, any code on the display and where the water appears.

Call from Wheaton

If your tankless heater is leaking in Wheaton or a nearby town such as Winfield or Carol Stream, call the number on this page. You will be connected with an independent provider. Wheaton Leak Repair Pros is a referral service and does not do the work itself.

Frequently asked questions

Can a tankless water heater leak?

Yes. Common sources are the water connections, the isolation valves, the condensate line and the heat exchanger.

Why is there water under my tankless heater?

It may be a loose fitting, a seal on a service valve, a blocked condensate line or an internal leak. Shut off the power and water and look at each.

What is condensate?

On condensing gas models, the exhaust is cooled and produces mildly acidic water that drains through a small line. A blocked or loose line can leak.

Does scale cause leaks in tankless heaters?

It can contribute by stressing the heat exchanger. Regular descaling is often recommended by manufacturers.

Can I repair a tankless heater myself?

Most repairs involve gas, electrical or sealed parts. Turn off the power, gas and water and call a licensed professional.

Should I replace a leaking tankless heater?

Not always. A seal or valve may be the whole problem. A provider can tell you whether the unit can be repaired.

Who does the work if I call this number?

An independent local provider. This website is a referral service and does not do repairs.

Tankless water heater leak repair in Wheaton, IL